This Colorado hiking trail provides a small gold mine of abandoned gold mines.

The highest bridge in America was built for an almost unnervingly small amount of money.

When ecosystems collide in the arid Southwest.

Hidden beneath a bridge, this waterfall is known for the large amounts of graffiti painted on its base.

This modern antique shop is a museum for 1980's Saturday morning cartoon culture.

This "zoo" is a cross between a junkyard and a sculpture garden, featuring animals you won't see anywhere else.

Wondrous sandstone hoodoos where Native Americans collected clay for pottery, 9,000 years ago.

Strange red rock formations that have been attributed to a higher power for hundreds of years.

This naturally-sourced hot spring is now home to a clothing-optional resort.

The largest self-built castle in the U.S., six decades in the making.

A breathtaking array of ancient Pueblo structures and artifacts counterintuitively preserved by neglect.

Crystal clear lake with a shoreline of travertine located in a Colorado canyon.

Current docking place of the SS United States, the fastest transatlantic ocean liner.

Yo, Adrian!

Dr Barnes' $25 billion private collection of art and arboretum.

This charming colonial alleyway is one of the oldest continuously used residential streets in the U.S.

Mural made of 100,000 pieces of hand blown glass, and until recently, the largest glass mural in the US.

Philadelphia boasts one of the best — and most often overlooked — traditional Japanese gardens in North America.

America's most famous museum of medical oddities is home to the remains of Albert Einstein's brain.

A layered tribute to the work of mosaicist Isaiah Zagar.

Arlington Cemetery exhibit dedicated to death and grieving.

North America's oldest quarantine facility was built in response to Philadelphia's 1793 yellow fever outbreak.

Descendants of this colonial Pennsylvania family still travel from far and wide to visit the 300-year-old home of their Quaker ancestors.

This might just be the TARDIS of bookstores.